1. Field of the Invention
The present invention relates to an RFID antenna using a kind of radio recognition technology called Radio Frequency Identification (RFID).
2. Description of the Related Art
In general, an radio frequency identification (hereinafter, called ‘RFID’) technology refers to a solution of using a radio frequency signal and reading non-contact type data stored in price tags, labels, or credit cards embedded in a small semiconductor chip to identify an object.
Such an RFID technology collects, stores, processes and tracks information of each item from tags attached to items using a radio frequency signal, capable of providing various services such as item location determination (LD), remote processing, management and information exchange among items.
In recent times, methods and systems for managing inventory, warehousing/goods delivery and item-selling using an RFID technology are proposed. For example, by installing an RFID antenna on a product management shelf for stocking or displaying items, attaching tags to each item, and grasping the current state of each item, a great number of items can be efficiently managed.
Item management methods/systems using an RFID, at locations where flow of stocked items is frequent and there are large users, may be conveniently applied to libraries, or rental stores, clothing shops where items are relatively displayed on a steady base.
Of late, a market is progressively and gradually expanding towards an RFID application field using ultra-high frequency (UHF) band (300 MHz˜3 GHz).
An RFID system of UHF band has an advantage in that it is capable of a tag recognition at a long recognition distance of more than 5 m, and it also has a very high recognition speed and a recognition ratio at a near-distance of less than 50 cm compared to that of HF band.
In such an RFID system of the UHF band, a farfield is mainly formed as an electric field, enabling tag recognition at a long distance, but it is sensitive to a surrounding environment because of being operated by back-scattering.
In an RFID system of UHF band, a nearfield is mainly formed as a magnetic field and operated by a coupling, and thus scarcely subject to an impact of materials having a high permittivity such as water or metal substances. As a result, an RFID reader advantageously has a high tag recognition ratio and is also fast in a recognition speed.